Oil, natural gas and natural gas liquids revenues were $64.1 million and $18.0 million for the three months ended June 30, 2021 and 2020, respectively. The increase in revenues in the most recent period is primarily attributable to an approximate $31.35 per Boe increase in our average realized prices (excluding the effects of hedging arrangements). The amount we realize for our production depends predominantly upon commodity prices, which are affected by changes in market demand and supply, as impacted by overall economic activity, weather, transportation take-away capacity constraints, inventory storage levels, quality of production, basis differentials and other factors. For the three months ended June 30, 2021 and 2020, production averaged 15,571 Boe/d and 14,264 Boe/d, respectively. Our average daily production increased in the three months ended June 30, 2021 when compared to the same period in the prior year due to new production brought online as a result of our 2021 capital program as well as production from wells brought back online that were shut-in during May and June 2020 when historically low commodity prices occurred, which was partially offset by third-party processing curtailments and facility upgrades and repairs in the current year period.
Lease operating expenses were $10.2 million and $10.3 million for the three months ended June 30, 2021 and 2020, respectively. On a per unit basis, lease operating expenses were $7.18 per Boe and $7.94 per Boe for the three months ended June 30, 2021 and 2020, respectively. The decrease in lease operating expenses in 2021 results from operational efficiencies decreasing our per unit costs.
Workover and other expenses were $0.8 million and $0.5 million for the three months ended June 30, 2021 and 2020, respectively. On a per unit basis, workover and other expenses were $0.54 per Boe and $0.42 per Boe for the three months ended June 30, 2021 and 2020, respectively. The increased workover and other expenses in 2021 relate to more significant workover projects undertaken in the current year.
Taxes other than income were $2.9 million and $1.5 million for the three months ended June 30, 2021 and 2020, respectively. Most production taxes are based on realized prices at the wellhead. As revenues or volumes from oil and natural gas sales increase or decrease, production taxes on these sales also increase or decrease. On a per unit basis, taxes other than income were $2.06 per Boe and $1.15 per Boe for the three months ended June 30, 2021 and 2020, respectively.
Gathering and other expenses were $14.3 million and $15.2 million for the three months ended June 30, 2021 and 2020, respectively. Gathering and other expenses include gathering fees paid to third parties on our oil and natural gas production and operating expenses of our gathering support infrastructure. Approximately $4.6 million and $2.3 million for the three months ended June 30, 2021 and 2020, respectively, relate to gathering and marketing fees paid to third parties on our oil and natural gas production. Gathering and marketing fees increased in 2021 as we marketed higher quantities of sour gas production to third parties in the current year period. Approximately $9.7 million and $9.5 million for the three months ended June 30, 2021 and 2020, respectively, relate to operating expenses on our treating equipment and gathering support facilities. The increase in treating equipment and gathering support facilities expenses in 2021 results from higher chemical costs to improve the quality of treated oil, which were partially offset by lower operating expenses associated with our treating equipment, as fewer sour gas production volumes were processed through our hydrogen sulfide treating plant in the current year period. Also included are $3.4 million of rig stacking charges for the three months ended June 30, 2020.
Restructuring expense was approximately $2.2 million for the three months ended June 30, 2020. During the three months ended June 30, 2020, we incurred restructuring charges related to the consolidation into one corporate office and had reductions in our workforce due to efforts to improve efficiencies and go forward costs. In May 2020, in furtherance of the consolidation into one corporate office, we exercised a one-time early termination option under the lease agreement for our office space in Denver, Colorado.
General and administrative expense was $3.5 million and $4.5 million for the three months ended June 30, 2021 and 2020, respectively. The reduction in general and administrative expense in the current period is associated with a decrease in professional fees and information technology costs incurred when compared to the prior year. On a per unit basis, general and administrative expenses were $2.50 per Boe and $3.45 per Boe for the three months ended June 30, 2021 and 2020, respectively.
Depletion for oil and natural gas properties is calculated using the unit of production method, which depletes the capitalized costs of evaluated properties plus future development costs based on the ratio of production for the current